Carbohydrate–protein interactions at interfaces: comparison of the binding of Ricinus communis lectin to two series of synthetic glycolipids using surface plasmon resonance studies
作者:P. Critchley、G. J. Clarkson
DOI:10.1039/b306784j
日期:——
Two C-lactosyl lipids and the related C-galactosyl lipids have been synthesised and their binding to RCA120 plant lectin was compared with a second series of thiolactosylethoxyalkanes. The interactions were measured quantitatively in real time by surface plasmon resonance (BIAcore) at a range of concentrations and temperatures from 5 to 30 °C. The C-galactosyl lipid (1,3-dimethyl-5-[β-D-galactopyranosyl]-5-(4-octadecyloxybenzyl)pyrimidine-2,4,6-trione) bound much more weakly with a KA
= 8.86 à 105 than the corresponding C-lactosyl lipid (1,3-dimethyl-5-[β-D-galactopyranosyl-(1 â 4)-β-D-glucopyranosyl]-5-(4-octadecyloxybenzyl)pyrimidine-2,4,6-trione)
(KA
= 2.31 Ã 107). The influence of the linker region of the two different series of lactosyl lipids was clearly demonstrated by the differences in the binding to RCA120 lectin. The changes in kinetic values and in the enthalpic and entropic contribution to the free energy of binding reflected the importance of the linker and the hydrocarbon anchor holding the synthetic glycolipids in the neomembrane.
合成了两种C-乳糖脂和相关的C-半乳糖脂,并将它们与RCA120植物凝集素的结合情况与第二系列的硫乳糖乙氧烷进行比较。通过表面等离子共振(BIAcore)在5至30°C范围内的不同浓度和温度下实时定量测量了互动。C-半乳糖脂(1,3-二甲基-5-[β-D-半乳糖吡喃糖基]-5-(4-辛烷基氧苯基)嘧啶-2,4,6-三酮)与RCA120的结合明显较弱,结合常数KA = 8.86 × 10^5,远低于相应的C-乳糖脂(1,3-二甲基-5-[β-D-半乳糖吡喃糖基-(1→4)-β-D-葡萄糖吡喃糖基]-5-(4-辛烷基氧苯基)嘧啶-2,4,6-三酮)(KA = 2.31 × 10^7)。两种不同系列乳糖脂的连接区域对RCA120凝集素结合的影响清晰可见,结合的动力学值以及自由能中焓和熵的变化反映了连接器及持有合成糖脂在新膜中的烃锚的重要性。